The present invention relates generally to scientific research and medical equipment. More particularly, the present invention relates to chambers which are provided with a controlled interior atmosphere such as an anaerobic incubator.
Various designs for anaerobic incubators exist, but all at the very least share these features: an enclosure with means for inducing and maintaining a prescribed environment; hand/arm access portals for manipulation of items within the controlled environment; and a pass box for moving samples in an out of the controlled environment. Prior art has dictated two designs for the shape of hand/arm portals, one design being circular as shown and described in U.S. Pat. No. 6,100,083 and the second design being best described as an elongated circle as shown and described in U.S. Pat. No. 5,861,305. In the '305 patent, the hand/arm portals are vertically elongated as compared to the circular portals, with their tops and bottoms remaining curved but with the sides only displaying a slight curvature.
Both the circular and elongated circular designs limit the scientist's movement within the controlled environment. Often samples are stored in the back of the enclosure or are introduced to the controlled environment via side pass boxes. Should the scientist or technician be small in stature and as such have a smaller reach, obtaining samples in the back of the enclosure is extremely difficult. Both the circular and elongated circular portals do not allow the scientist to get his/her upper arm and shoulder into the enclosure. Additionally, for anaerobic incubators where the pass boxes are located on the side of the incubator, all scientists have mobility issues, because human elbows are not designed to bend away from the body (i.e. backwards). Moving samples to/from side pass boxes or enclosures is extremely awkward. Due to the shape of the hand/arm portals it is extremely difficult to maneuver one's left arm to reach a sample contained within a pass box on the right-hand side of the enclosure, because the distance is simply too great; while reaching the sample with one's right-hand is also difficult due to the elbow's inability to move in backward.